To demand to go to the bathroom first, claiming that you will be faster because all you have to do is urinate, but then while you are on the toilet, you start taking a crap.

Man, when my roommate got home from the bar, I really had to go to the bathroom, but he claimed he should go first because he only had to piss, but once he got on there, I could smell him, he pulled a piss and switch, and I was stuck waiting outside the bathroom for 15 minutes!